/*
   Copyright (c) 2012 LinkedIn Corp.

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
*/

package com.linkedin.d2.balancer.util.hashing;

import java.util.Iterator;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;


/**
 * @implNote The implementation of this interface should not override equal and hashCode
 */
public interface Ring<T>
{
  /**
   * Pick an object in the ring given a specified key
   *
   * @param key   The value used to pick an object from the hash ring
   * @return An object in the ring
   */
  @Nullable
  T get(int key);

  /**
   * Get an iterator of the objects in the ring given a specified key
   *
   * @param key parameter might specify the starting point of the map on the ring or just be ignored
   * @return  An iterator of the objects in the ring
   */
  @Nonnull
  Iterator<T> getIterator(int key);

  boolean isStickyRoutingCapable();

  boolean isEmpty();
}
